Dodge RAM TRUCK 1500 1995 Service Manual page 1394

BR
42RH/46RH/47RH TRANSMISSION DIAGNOSIS AND TESTING 21 -111
(1586-1931 kPa) as lever is moved rearward.
Test Five—Governor Pressure
This test checks governor operation b y mea­
suring governor pressure response to changes
i n engine speed. I t is usually not necessary to
check governor operation unless shift speeds
are incorrect o r i f the transmission w i l l not
downshift, or upshift.
(1) Connect 100 psi Test Gauge C-3292 to governor
pressure port.
(2) Move transmission shift lever to D range.
(3) Start and run engine at curb idle speed and
note pressure. At idle and with vehicle stopped, pres­
sure should be zero to 1-1/2 psi maximum. If pres­
sure exceeds this figure, governor valve or weights
are sticking open.
(4) Slowly increase engine speed and observe
speedometer and pressure test gauge. Governor pres­
sure should increase in proportion to vehicle speed.
Or approximately 1 psi for every 1 mph.
(5) Pressure rise should be smooth and drop back
to 0 to 1-1/2 psi when wheels stop rotating.
(6) Compare results of pressure tests with analysis
chart (Fig. 4).
Test Six—Transmission In Overdrive Fourth Gear
This test checks line pressure a t the over­
drive clutch in fourth gear range. Use 300 psi
Test Gauge C-3292 for this test. Perform the test
on the road, or on a chassis dyno.
(1) Turn overdrive selector switch to ON position
(2) Raise vehicle and connect test gauge to over­
drive clutch pressure port (Fig. 3).
(3) Lower vehicle. Then route test gauge to driver
window. Secure gauge where it can be viewed from
drivers seat.
(4) Take vehicle out onto road, or position it on
chassis dyno.
(5) Start engine and shift into D range.
(6) Increase engine rpm gradually until 3-4 shift
occurs and note gauge pressure.
(7) Pressure should be 469-496 kPa (68-72 psi)
with closed throttle and increase to 620-827 kPa (90-
120 psi) at 1/2 to 3/4 throttle. Note that pressure will
increase to 896 kPa (130 psi) or more at full throttle.
(8) Refer to pressure test analysis chart (Fig. 4) for
pressure diagnosis.
CONVERTER STALL TEST
Stall testing involves determining maximum engine
rpm obtainable at full throttle with the rear wheels
locked and the transmission in D range. This test
checks the holding ability of the the converter over­
running clutch and both of the transmission clutches.
TEST CONDITION
Line pressure OK during
any one test
Line Pressure OK in R
but low in D, 2, 1
Pressure Low in D
Fourth Gear Range
Pressure OK in 1, 2 but
low in D3 and R
Pressure OK in 2 but low
in R and 1
Front servo pressure low
in 2
Pressure low in all positions
Governor pressure too high
| at idle speed
Governor pressure low
at all mph figures
Lubrication pressure low at
all throttle positions
INDICATION
Pump and regulator valve OK
Leakage in rear clutch area (servo,
clutch seals, governor tubes)
Overdrive clutch piston seal, or
check ball problem
Leakage in front clutch area (servo,
clutch seals, retainer bore, pump
seal rings)
Leakage in rear servo
Leakage in servo; broken servo
ring or cracked servo piston
Clogged filter, stuck regulator
valve, worn or faulty pump,
plugged fluid cooler
Governor valve sticking open
Governor valve sticking closed
Clogged oil cooler, lines, drain-
back valve, seal rings leaking, output
shaft plugged with debris, worn
bushings in pump or clutch retainer
J952H69
Fig. 4 Pressure Test Analysis
REAR DURING A STALL TEST ALWAYS BLOCK
THE WHEELS AND APPLY THE SERVICE AND
PARKING BRAKES DURING THE TEST
STALL TEST PROCEDURE
(1) Connect tachometer to engine. Position tachom­
eter so it can be viewed from driver seat.
(2) Check transmission fluid level. Add fluid if nec­
essary.
(3) Drive vehicle to bring transmission fluid up to
normal operating temperature. Vehicle can be driven
on road, or on chassis dyno if shop is so equipped.
(4) Block front wheels.
(5) Fully apply service and parking brakes.
(6) Open throttle completely and record maximum
engine rpm registered on tachometer. It takes 4-10
seconds to reach max rpm. However, once max
rpm h a s been achieved, do not hold wide open
throttle for more t h a n 4-5 seconds.
WARNING: NEVER ALLOW ANYONE TO STAND DI­
RECTLY IN LINE WITH THE VEHICLE FRONT OR